Typically in Severums you could try to decipher whether it's a female or male by how many marks they have near their face. But with your particular Severum it's a little to young to tell if it's a female or male even by the facial markings. Once the Severum gets about 5 1/2 - 6 Inches and more towards sexual maturity you'll tell if it's a female by either if the fish lays eggs, even if the fish hasn't had any eggs notice if the fish's anal area hangs relatively low, or sometimes by the average aggression patterns in Male or Female Severums. Keep us updated please!